• Title/Summary/Keyword: Cascading

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Control strategy against undesirable zone 3 protection with respect to voltage collapse (전압붕괴 측면에서의 Zone3 보호동작 억제를 위한 제어방안)

  • Song, Hwa-Chang;Lee, Byong-Jun
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.24-26
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    • 2005
  • This paper presents a framework for determining control strategies against unwanted tripping actions of relay operation that plays a very important role in cascading events leading to voltage collapse. The framework includes an algorithm for quick identification of possible zone 3 relay operation during voltage instability. The proposed approach comes up with control strategy of load shedding at the selected location with active power and relay margin criteria. In addition, Quasi Steady-State (QSS) simulation is employed to obtain time-related information which is valuable for both the timing and amount of control. The methodology is demonstrated through the modified New England 39-bus system.

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A hand gesture recognition method for an intelligent smart home TV remote control system (스마트 홈에서의 TV 제어 시스템을 위한 손 제스처 인식 방법)

  • Kim, Dae-Hwan;Cho, Sang-Ho;Cheon, Young-Jae;Kim, Dai-Jin
    • Proceedings of the Korean Information Science Society Conference
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    • 2007.10c
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    • pp.516-520
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    • 2007
  • This paper presents a intuitive, simple and easy smart home TV remote control system using the hand gesture recognition. Hand candidate regions are detected by cascading policy of the part of human anatomy on the disparity map image, Exact hand region is extracted by the graph-cuts algorithm using the skin color information. Hand postures are represented by shape features which are extracted by a simple shape extraction method. We use the forward spotting accumulative HMMs for a smart home TV remote control system. Experimental results show that the proposed system has a good recognition rate of 97.33 % for TV remote control in real-time.

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IDENTIFICATION OF EROSION PRONE FOREST AREA - A REMOTE SENSING AND GIS APPROACH

  • Jayakumar, S.;Lee, Jung-Bin;Enkhbaatar, Lkhagva;Heo, Joon
    • Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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    • 2008.10a
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    • pp.251-253
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    • 2008
  • Erosion and landslide cause serious damage to forest areas. As a consequence, partial or complete destruction of vegetation occurs, which leads to many cascading problems. In this study, an attempt has been made to identify the forest areas, which are under different risk categories of erosion and landslide, in part of Eastern Ghats of Tamil Nadu. Relevantthematic maps were generated from satellite data, topographical maps, primary and secondary data and weights to each map were assigned appropriately. Weighted overlay analysis was carried out to identify the erosionprone forest areas. The result of erosion and landslide prone model reveals that 4712 ha(17%) of forest area is under high risk category and 15879 ha(58.65%) isunder medium risk category. The results of spatial modeling would be very much useful to the forest officials and conservationist to plan for effective conservation.

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A Design of 2-D Zero-Phase IIR Digital Filter with Narrow Transition Band (협대역 변이영역을 갖는 2차원 영위상 IIR 디지털 필터의 설계)

  • 김훈학;연형태;이근영
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.12
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    • pp.1940-1946
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    • 1990
  • In this paper, we are proposed a 2-D zero-phase IIR second-order filter which have separable denominators. The filter combines the advantages of the separable denominator and the simplicity of the McClellan transform. Generally, the McClellan transformation is not suitable for IIR filter because the 1-D to 2-D substibution can not be achieved easily in most of denominators. So we have designed the second order denominator using a separable condition via a first order McClellan transformation. The implementation of a higher order filter can be achieved by cascading such second order parts with different coefficients in denominator. As a result, we have suppressed the ripples in stopband and obtained the narrow transition band.

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A Development of Software about Short-circuit Calculation and Protective-coordination (고장계산 및 보호협조 판정 소프트웨어 개발)

  • Park, S.C.;Choe, J.H.;Seo, J.M.
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.159-162
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    • 2002
  • A software, called touch-one, is developed about the determination of short-circuit values and protective co-ordination in power system. The used solution algorithm reviewed intensively, and the protective co-ordination determination technique presented by using the circuit-breaker's current-limitation characteristic. The protective coordination concerns the behaviour of two devices placed in series in an electrical network, with a short-circuit downstream circuit-breaker. It has two basic principles: First, discrimination which is an increasing requirement of low voltage electrical distribution systems. Second, which is less well known: cascading, which consists of installing a device, whose breaking capacity is less than the three-phase short-circuit current at its terminals and helped by main circuit-breaker. With this software, we can construct a electric-power system which is reliable and economic according to user's purpose.

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BRMS기반 학과BSC

  • Park, Jong-Cheol;Park, Chung-Sik;Kim, Jae-Hong;Gang, Eun-Ji
    • Proceedings of the Korea Database Society Conference
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    • 2010.06a
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    • pp.99-107
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    • 2010
  • BSC(Balanced Scorecard)는 재무적 성과지표의 한계를 지양하고 고객관점, 내부 프로세스 관점, 학습과 성장 관점, 재무 관점의 다양한 관점에서 성과측정시스템으로 상용 될 수 있을 뿐만 아니라 전략의 해석, 전략적 캐스케이딩(cascading), 전략적 자원분배, 전략적 학습도구를 위한 전략관리시스템으로 또한 의사소통도구로서 사용된다. 분 논문에서는 대학내의 학과들이 각각 개별적인 특성이 존재하고 학과의 제한된 자원과 역량하에서의 효율적인 운영과 이에 대한 조직적인 접근방법이 필요하기 때문에 학과조직에 BSC를 적용하는 방안을 모색하였다. 이러한 학과 BSC는 대학 전체 또는 그 상위조직의 BSC를 위한 토대로 이용될 수 있을 뿐만 아니라 교육에 관련한 다양한 인증 및 평가와 연계할 수 있을 것이다. 또한 본 논문에서는 최소한의 프로그래밍과 이해하기 용이한 수행규칙, 그리고 유연한 개정을 위하여 비즈니스 규칙(Business Rule)으로 이루어지는 BRMS(Business Rule Management System)로 학과 BSC를 설계할 수 있는 방안을 모색하였다.

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Analysis and Design of Low Pass Filter using Unit Cell based on CRLH Transmission Line

  • Yang, Lei;Yang, Doo-Yeong
    • International Journal of Contents
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    • v.8 no.3
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    • pp.100-104
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    • 2012
  • In this paper, a unit cell for low pass filter design by using composite right and left-handed transmission line in conductor-backed coplanar waveguide is proposed. The characteristics of the unit cell are analyzed in order to design a low pass filter in small sizes. By changing the sizes of the unit cell, the parameters of right-handed and left-handed immittance components are changed and the desired characteristics of the unit cell are achieved. The equivalent circuit of the unit cell is extracted and analyzed either. As a result, the simulation results of the unit cell and the equivalent circuit are almost identified. The movement and energy distributions of electromagnetic field are shown to confirm the property of the unit cell. In the end, a low pass filter is demonstrated by cascading three proposed unit cells, which shows cutoff frequency of 1.53GHz and deep attenuation from 2.23GHz to 4.49GHz lower than -50dB.

Speech Enhancement Using Blind Signal Separation Combined With Null Beamforming

  • Nam Seung-Hyon;Jr. Rodrigo C. Munoz
    • The Journal of the Acoustical Society of Korea
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    • v.25 no.4E
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    • pp.142-147
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    • 2006
  • Blind signal separation is known as a powerful tool for enhancing noisy speech in many real world environments. In this paper, it is demonstrated that the performance of blind signal separation can be further improved by combining with a null beamformer (NBF). Cascading the blind source separation with null beamforming is equivalent to the decomposition of the received signals into the direct parts and reverberant parts. Investigation of beam patterns of the null beamformer and blind signal separation reveals that directional null of NBF reduces mainly direct parts of the unwanted signals whereas blind signal separation reduces reverberant parts. Further, it is shown that the decomposition of received signals can be exploited to solve the local stability problem. Therefore, faster and improved separation can be obtained by removing the direct parts first by null beamforming. Simulation results using real office recordings confirm the expectation.

Cascade Realization of Conservative Logic Circuits (Conservative 논리회로의 종속실현)

  • Koh, Kyung-Shik;Jun, Kyong-Il
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.17 no.6
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    • pp.93-98
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    • 1980
  • In this paper, the principles of cascade realization o( conservative logic circuits are explored and the problem of realizing arbitrary 3-3 logic circuit with mini mal number of logic elements is handled, The five primitive classes 5, 15, 21, 24 and 29 are selected to realize all of the 31 equivalent c]asses by cascading only two of them. The crossovers of lines are permitted in this realization 3nd the upper bound of crossovers is three. The results are summarized and listed in a table.

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A Study on Decentralized under Voltage Load Shedding Scheme for Preventing Wide-area Black Out (광역정전 예방을 위한 분산형 부하 제어 방안에 대한 연구)

  • Lee, Yun-Hwan
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.63 no.1
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    • pp.1-6
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    • 2014
  • An electric power system sometimes fails because of disturbances that occur unexpectedly, such as the uncontrolled loss of load that developed from cascading blackout. Which make stability through a little of under voltage load shedding should work. The development of phasor measurement unit(PMU) makes network supervision possible. The information obtained from PMU is synchronized by global positioning system(GPS). There are many real-time algorithms which are monitoring the voltage stability. This paper presents the study on the VILS(Voltage Instability Load Shedding) using PMU data. This algorithm computes Voltage Stability Margin Index(VSMI) continuously to track the voltage stability margin at local bus level. The VSMI is expressed as active and reactive power. The VSMI is used as an criterion for load shedding. In order to examine the algorithm is effective, applied to KEPCO system.